Taper and mastic applicator



y 12, 1966 J. c. HOVELAND TAPER AND MASTIC APPLICATOR Filed May 29, 1962INVENTUR ATTDP N EY United States Patent 3,260,638 TAPER AND MASTICAPPLICATGR Julian Cleon Hoveland, Edmonton, Alberta, Canada, as-

signor to Merrill D. Muttart, Edmonton, Alberta, Canada Filed May 29,1962, Ser. No. 198,610 2 Claims. (Cl. 156575) This device relates to animproved dry wall taper and mastic applicator.

Dry wall taping and mastic applicating devices are well known andgenerally these comprise a mastic barrel with a roll of tape carried bythe barrel and with some form of tape applying means at the forward endof the barrel. The tape applying means usually comprises spaced wheelsover which the tape is passed and there is a piston in the mastic barrelthat is coupled to the tape applying wheel so that movement of thewheels results in the piston ejecting mastic from the barrel. Theejection of mastic from the barrel usually is by way of a nozzle that isused to apply the mastic to the tape so that the mastic covered tape maybe rolled in position to cover a dry wall joint.

The chief difficulty in prior devices of this sort is that the mastic isapplied only to one side of the tape, that is to say, the side of thetape that will be pressed against the wall and the opposite side of thetape is dry. This makes for difliculty when the joint is trowelled topress the tape particularly in a corner since the dry tape tends to dragon the trowel as the trowelling operation proceeds and time and effortmust be spent to achieve a satisfactory finish.

Eiforts to overcome this have been in the direction of applying moremastic to the underside of the tape so that when the tape is pressedinto the wall surface the excess mastic would be squeezed out the sideof the tape and then used as a lubricant on the dry tape face. Whilethis has been satisfactory to a degree, the excess of mastic squeezingfrom the side of the tape has resulted in a messy and untidy operationand considerable mastic is lost during the finishing.

Since it is necessary, in prior devices of this sort, to cut off thetape when taping a dry wall joint, it has also been necessary to providesome form of tape feeding means whereby the end of the tape may be movedinto contact with the tape applying wheels. Since the ejection of masticfrom the barrel is coupled to movement of the tape applying wheels, itwill be obvious that movement of the tape by the tape feeding means tobring the end of tape into contact with the tape applying wheels willresult in a section of the tape being without mastic and it usually hasbeen necessary to use some form of manual means to apply mastic to thisportion of the tape or to the portion of the joint to be covered by thistape.

An additional disadvantage is to be found in the fact that the masticbarrel is of opaque construction and to eliminate the danger of thepiston in the barrel becoming fouled at the end of the barrel, theregenerally is provided some form of disengaging mechanism that disengagesmovement of the piston once it has progressed dangerously close to thebarrel end.

A further disadvantage in prior apparatus of this nature may be found inthe use of a nozzle at the barrel end to discharge mastic onto themoving tape. The use of a nozzle necessitates that there must always bemovement of the piston in the barrel to place the mastic under pressureso that it will be discharged positively onto the tape and, should therebe no movement of the piston in the barrel to place the mastic underpressure, no mastic will be discharged on the tape and sections of thetape may be left without mastic.

3,260,638 Patented July 12, 1966 I have overcome the above and otherdisadvantages in devices of this sort by firstly constructing my devicewith a mastic chamber at the forward end of the barrel wherein aquantity of mastic may be stored at all times. Further, I have provideda pair of spaced guide plates within my mastic chamber for guiding thetape through the chamber and which serve to divide the chamber intoupper and lower compartments.

Openings through the guide plates are provided for the passage of masticfrom the upper to the lower compartment and additional openings in theplates are provided so that the tape passing through the mastic chambermay pick up mastic on either or both of its sides prior to its passagefrom the guide plates onto the tape applying means.

Control of the flow of mastic from the upper to the lower compartmentsand of mastic onto either or both sides of the tape is accomplishedthrough simple manually operated valves that may be actuated as desired.

To eliminate the difiiculty of a portion at the end of the tape beingwithout mastic as the tape is advanced, I have associated movement ofthe piston within the mastic barrel with a drive wheel in frictionalcontact with the moving tape prior to the passage of the tape into themastic chamber. In this way, whenever the tape is advanced by the tapeadvancing means, the drive wheel will be brought into operation and thiswill move the piston in the barrel to force mastic out of the barrelinto the mastic chamber.

I have found that this system for moving the piston in the masticchamber is a considerable advantage over prior systems in that itrequires only a change in the diameter of the drive wheel to accelerateor retard movement of the piston in the barrel and thereby controlmovement of mastic from the barrel.

Further, to eliminate disengaging mechanism that prevent damage to thepiston striking the end of the barrel I have adopted the simpleexpedient of making the entire mastic barrel of translucent material sothat movement of the piston, condition of the mastic and generaloperation of the machine is visible to the operator at all times.

With reference now to the drawings illustrating a preferred embodiment:

FIG. 1 is an enlarged broken away sectional side elevation illustratingthe mastic chamber and the piston driving mechanism.

FIG. 2 is a projected view of the complete machine illustrating theplacement of the tape and passage of the tape onto the tape applyingmeans and the tape cutter.

FIG. 3 is a broken away projected enlarged view of the mastic chamberand guide plates.

With reference now to the drawings, my device comprises the elongatedmastic barrel indicated generally at 1 which isclosed at its rearwardend and provided with a handle 2 and which exhausts at its forward end39 into the mastic chamber indicated generally at 3.

The mastic chamber 3 is formed by a housing comprising rear wall 3a,forward wall 3b, side walls 30, bottom wall 3d, and top wall 3e.

As is customary in devices of this sort, a reel of tape 4 is carried bythe barrel 1 on the axle 5 and the tape 6 passes to the guide mechanismindicated generally at 7 and from the guide mechanism 7 through themastic chamber 3 to the tape applying wheels 8. Since the tape applyingwheels are more or less standard in this type of apparatus it is notconsidered that further explanation of these is necessary.

Included in the tape guide means 7 is the tape advancing mechanismconsisting of the prongs 9 secured to the block 10 which is in turnsecured to the bar 11. The bar 11 is coupled through the linkage 12 and13 to the sleeve 14 on the barrel 1 so that forward movement of thesleeve 14 with relation to the barrel 1 will bring the prongs 9 intocontact with the tape and advance the tape forwardly. A spring 15 servesto maintain the sleeve 14 normally in a rearward or retracted positionwith the prongs 9 out of contact with the tape 6. With this mechanism itwill be obvious that reciprocation of the sleeve 14 on the barrel 1 willengage the prongs 9 with the tape on forward movement and disengage thepins on rearward movement and will thereby advance the tape 6 insuccessive steps.

In the mastic chamber 3 I have provided the pair of guide plate 16 and17 which are positioned in the mastic chamber in spaced parallelrelationship to receive the tape from the tape guide 7 and transfer thetape through the mastic chamber to the tape wheels 8. It should be notedthat the guide plates 16 and 17 divide the mastic chamber into an uppercompartment 18 and a lower compartment 19 and that the width of theplates 16 and 17 is less than the width of the mastic chamber. Thisleaves spaces 20 between the sides of the plates 16 and 17 and the sidesof the mastic chamber through which mastic can flow from the uppercompartment 18 to the lower compartment 19.

The plates 16 and 17 are also reduced in width at their forward ends asindicated at 21 to provide additional openings whereby the tape 6passing therethrough can pick up mastic on either of its sides.

Since it is not always desirable or advisable to apply mastic to bothsides of the tape simultaneously, and since it is necessary to close ofithe openings 20 and 21 when the barrel 1 is being filled, I haveprovided the flap valves 22 and 23 mounted on axles extending throughthe mastic chamber with tabs 24 and 25 which may be actuated manually toopen and close the flap valves 22 and 23 respectively.

The piston 26 is mounted slidably within the barrel and is connected tothe rack 27 which extends rearwardly from the piston substantiallycoaxially in the barrel 1 and is interconnected with the pinion 28. Thepinion 28 is in turn driven from the gears 29 and the bevel gear 30 inengagement with the bevel gear 31 on the flexible drive shaft 32. Theflexible drive shaft 32 is connected to the roller wheel 33 which ismounted rotatably to the arm 34 to engage with the idler wheel 35through the slot 36 in the guide means 7. Adjustment of the tensionbetween the roller wheel 33 and the idler 35 is accomplished through thespring 37 adjustable by the wing nut 38.

Obviously, as the tape 6 passes between the idler 35 and the roller 33,the roller 33 will be rotatedand through the bevel gears 30-31 and thegear 29 the pinion 28 will be actuated to move the rack 27 and, therebythe piston 26, to force mastic through the end 39 of the barrel 1 intothe mastic chamber 3.

Loading of the mastic barrel 1 is accomplished through the one way valve40 which will allow mastic to be pumped through the valve into thebarrel but will close and prevent the passage of any mastic in theopposite direction.

The tape cut off is accomplished through the knife blade 41 whichoperates vertically in the posts 42 in the manner of a guillotine and isconnected through the links 43 and 44 to the lateral bar 45. The bar 45is connected to the actuating arm 46 which is, in turn, connectedthrough the link 47 to the bar 48 formed downwardly at 49 to engage withthe end of the bar 13 on the sleeve 14. With this connection, wheneverthe sleeve 14 is moved rearwardly the arm 46 will be moved to rotate thebar 45 and lower the knife 41 to sever the tape below the knife. Aspring 50 coacting between one end of the arm 46 and the exterior of themastic chamber serves to hold the knife 41 normally in the up ornon-cutitng position.

In operation, the mastic barrel 1 would be filled as described byconnecting a feed pipe to the one way valve 40 and with the flap valves22 and 23 closed, mastic would 4 then be forced into the barrel 1 tomove the piston 26 rearwardly until the barrel were full.

Thereafter, the roll of tape 6 would be fed through the tape guide 7between the idler 35 and roller 33 and up to the mastic chamber 3. Theflap valves 22 and 23 then would be opened and thereafter the sleeve 14would be actuated to move the tape 6 through the mastic chamber 3 and tothe tape applying wheels 8. During passage of the tape through themastic chamber 3 the tape would be covered with mastic either on one orboth sides as desired, so that the tape when in contact with the tapeapplying wheels 8 would have sufficient mastic thereon for applicationto a wall surface.

If a flat wall joint were to be covered, the machine would be operatedin standard fashion to roll the tape over the tape joint and the tapecutter would be actuated to cut off the tape at the desired point.

Should the tape be applied in a corner, the corner applying wheel 51would then be moved forwardly on its arms 52 to depress the centre ofthe tape into the corner. Since the corner applying wheel 51 on arms 52is of common construction it is not considered necessary of furtherdescription.

It will now be seen that I have provided a combined dry wall taper andmastic applicator wherein the tape may be coated on one or both sides asdesired with mastic to facilitate the application of the tape to a flatWall surface or in a corner. Further, I have provided apparatus of thissort wherein the application of mastic to the tape is independent ofrotation of the tape applying wheels and is governed by movement of thetape so that the tape will at all times have mastic thereon.

What I claim as my invention is:

1. A dry wall taper and mastic applicator comprising an elongatedmastic-receiving barrel, a mastic-ejecting piston slidably mounted insaid barrel, a housing mounted on one end of said barrel and having rearand forward walls, top and bottom walls, and side walls forming amastic-receiving chamber communicating with the interior of said barrel,a pair of spaced parallel tape guide plates extending through said rearand forward walls and said chamber, said plates being spaced from saidtop and bottom walls and defining a lower portion of said chamberbetween said plates and said bottom wall and an upper portion of saidchamber between said plates and said top wall, said plates having edgesspaced from said side walls and defining mastic flow passagescommunicating with said chamber portions, one of said plates havingtapeexposing openings therein adjacent said forward wall andcommunicating directly with said lower portion of said chamber, theother of said plates having tape-exposing openings therein adjacent saidforward wall and communicating directly with said upper portion of saidchamber.

2. A dry wall taper and mastic applicator as defined in claim 1, saidupper chamber portion being in direct communication with the interior ofsaid barrel, valve means in said housing actuatable to open and closesaid mastic flow passages and said plate openings, and means externallyof said housing for actuating said valve means.

References Cited by the Examiner UNITED STATES PATENTS 1,711,257 4/1929Apfelbaum 156-357 2,288,987 7/1942 Allen 156-575 2,317,446 4/1943 Dennis156-357 2,323,963 7/1943 Ames 156-575 2,502,499 4/ 1950 Ames 156-5743,116,195 12/ 1963 Lathrop et a1. 156-575 EARL M. BERGERT, PrimaryExaminer. R. 1. SMITH, M. L. KATZ, Examiners.

1. A DRY WALL TAPER AND MASTIC APPLICATOR COMPRISING AN ELONGATEDMASTIC-RECEIVING BARREL, A MASTIC-EJECTING PISTON SLIDABLY MOUNTED INSAID BARREL, A HOUSING MOUNTED ON ONE END OF SAID BARREL AND HAVING REARAND FORWARD WALLS, TOP AND BOTTOM WALLS, AND SIDE WALLS FORMING AMASTIC-RECEIVING CHAMBER COMMUNICATING WITH THE INTERIOR OF SAID BARREL,A PAIR OF SPACED PARALLEL TAPE GUIDE PLATES EXTENDING THROUGH SAID REARAND FORWARD WALLS AND SAID CHAMBER, SAID PLATES BEING SPACED FROM SAIDTOP AND BOTTOM WALLS AND DEFINING A LOWER PORTION OF SAID CHAMBERBETWEEN SAID PLATES AND SAID BOTTOM WALL AND AN UPPER PORTION OF SAIDCHAMBER BETWEEN SAID PLATES AND SAID TOP WALL, SAID PLATES HAVING EDGESSPACED FROM SAID SIDE WALL AND DEFINING MASTIC FLOW PASSAGESCOMMUNICATING WITH SAID CHAMBER PORTIONS, ONE OF SAID PLATES HAVINGTAPEEXPOSING OPENINGS THEREIN ADJACENT SAID FORWARD WALL ANDCOMMUNICATING DIRECTLY WITH SAID LOWER PORTION OF SAID CHAMBER, THEOTHER OF SAID PLATES HAVING TAPE-EXPOSING OPENINGS THEREIN ADJACENT SAIDFORWARD WALL AND COMMUNICATING DIRECTLY WITH SAID UPPER PORTION OF SAIDCHAMBER.
 2. A DRY WALL TAPER AND MASTIC APPLICATOR AS DEFINED IN CLAIM1, SAID UPPER CHAMBER PORTION BEING IN DIRECT COMMUNICATION WITH THEINTERIOR OF SAID BARREL, VALVE MEANS IN SAID HOUSING ACTUATABLE TO OPENAND CLOSE SAID MASTIC FLOW PASSAGES AND SAID PLATE OPENINGS, AND MEANSEXTERNALLY OF SAID HOUSING FOR ACTUATING SAID VALVE MEANS.